Darkcrest Strategist Potential Bug

Hello,

I would like to preface this with: I am unsure of if this is actually a bug or not (Hence the “potential” in the post title)

I just played a hearthstone battleground game where I had a golden darkcrest strategist (The Tier 5 naga with Spellcraft: Get a random Naga who upgrades it’s tier at the end of the turn) wherein I reached the point where I was able to get tier 6 nagas for several turns in a row (a total of around 9 units). However, whenever I used the spellcraft, I did not get a single Groundbreaker, Tidemistress Athissa, Silivaz the Vindictive, or Slitherspear, Lord of Gains. Instead, I only generated Arid Atrocities and One-Amalgam Tour Groups.

There was one other player with any Nagas in the lobby and he only had a golden Slitherspear, Lord of Gains.

While I know this is possible, it feels that with so many Naga still available in the pool, it is highly unlikely to generate not a single one of them from the spellcraft. Has anyone else experienced something similar or was I just unlucky?